The Computer Laboratory is the computer science department of the University of Cambridge. As of 2007, it employs 35 academic staff, 25 support staff, 35 affiliated research staff, and about 155 research students. The current head of department is Professor Andy Hopper.

A number of companies have been founded by staff and graduates. Their names were featured in the new laboratory entrance in 2012.[15] Some cited examples of successful companies are ARM, Autonomy, Aveva, CSR and Domino. One common factor they share is that key staff or founder members are "drenched in university training and research".[16] The Cambridge Computer Lab Ring was praised for its "tireless work" by Andy Hopper in 2012, at its tenth anniversary dinner.[17]

It was founded as the Mathematical Laboratory under the leadership of John Lennard-Jones on 14 May 1937, though it did not get properly established until after World War II. The new laboratory was housed in the North Wing of the former Anatomy School, on the New Museums Site. Upon its foundation, it was intended to provide a computing service for general use, and to be a centre for the development of computational techniques in the University. The Cambridge Diploma in Computer Science was the world’s first postgraduate taught course in computing, starting in 1953.

In October 1946, work began under Maurice Wilkes on EDSAC (Electronic Delay Storage Automatic Calculator), which subsequently became the world’s first fully operational and practical stored program computer when it ran its first program on 6 May 1949. It inspired the world’s first business computer, LEO. It was replaced by EDSAC 2, the first microcoded and bitsliced computer, in 1958.

In 1970, the Mathematical Laboratory was renamed the Computer Laboratory, with separate departments for Teaching and Research and the Computing Service, providing computing services to the university and its colleges. The two did not fully separate until 2001, when the Computer Laboratory moved out to the new William Gates building in West Cambridge, off Madingley Road, leaving behind an independent Computing Service.